1. Field
The disclosure relates generally to wireless systems and methods, and, in particular, to systems and methods for beacon detection.
2. Background
Wireless communication systems are widely deployed to provide various types of communication content such as, for example, voice, data, and so on. Typical wireless communication systems may be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple-access systems may include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and the like. Additionally, the systems can conform to specifications such as third generation partnership project (3GPP), 3GPP long-term evolution (LTE), ultra mobile broadband (UMB), evolution data optimized (EV-DO), etc.
Generally, wireless multiple-access communication systems may simultaneously support communication for multiple mobile devices. Each mobile device may communicate with one or more access points via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from access points to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to access points. Further, communications between mobile devices and access points may be established via single-input single-output (SISO) systems, multiple-input single-output (MISO) systems, multiple-input multiple-output (MIMO) systems, and so forth. In addition, mobile devices can communicate with other mobile devices (and/or access points with other access points) in peer-to-peer wireless network configurations.
To supplement conventional access points, additional restricted access points can be deployed to provide more robust wireless coverage to mobile devices. For example, wireless relay stations and low power access points (e.g., which can be commonly referred to as Home NodeBs or Home eNBs, collectively referred to as H(e)NBs, femto access points, femtocells, picocells, microcells, etc.) can be deployed for incremental capacity growth, richer user experience, in-building or other specific geographic coverage, and/or the like. In some configurations, such low power access points can be connected to the Internet via broadband connection (e.g., digital subscriber line (DSL) router, cable or other modem, etc.), which can provide the back haul link to the mobile operator's network. Thus, for example, the low power access points can be deployed in user homes or enterprise environment to provide mobile network access to one or more devices via the broadband connection.
In such heterogeneous networks, it is often challenging for a mobile device and a nearby access point, such as a small cell, to detect each other. One challenge lies in that there is an incentive for the small cell to remain in power-save mode for extended periods when there are no mobile devices in the coverage area of the small cell. Detection, and therefore communication, between the devices (e.g., when the mobile device returns to the coverage area) is limited while the small cell is in the power-save mode. One prior solution is for the small cell to transmit low-power beacons so that the mobile device can detect the presence of the small cell in power-save mode.